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  • Author or Editor: C. J. Nelson x
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Abstract

The rate and total germination of cucumber (Cucumis sativus L.) seeds incubated at 12°C was markedly increased by acetone infusion with fusicoccin (FC). Gibberellic acid (GA4/7) was less effective than FC but more effective than GA3 or (2-chloroethyl)phosphoric acid (ethe-phon) in promoting rapid germination. Infusion of GA4/7 alone or in combination with kinetin and/or ethephon into muskmelon (Cucumis melo L.) seeds increased total germination at 16°C The growth regulators were generally not effective in promoting low temperature germination of watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) seeds.

Open Access

Abstract

(2-chlorethyl)trimethylammonium Chloride (chlormequat) sprayed on tipped Clusters of girdled ‘Cardinal’ grape (Vitis vinifera L.) at 250 to 1000 ppm during bloom increased the number of seeded berries per Cluster but reduced berry weight Heavy Cluster thinning increased berry weight on chlormequat treated Clusters. Succinic acid-2,2-dimethylhydrazide (SADH) did not increase seeded berry set or affect any of the other fruit characteristics measured at the concentrations tested. The synthetic cytokinin, 6-(benzylamino)-9-(2-tetrahydropyranyl)-9H purine (PBA), resulted in a marked increase in seeded berries at 300 ppm, but the number of shot-berries was also increased.

Open Access
Authors: and

Abstract

The rate and total emergence of lettuce (Lactuca sativa L. ‘Empire’) seedlings incubated at 33°C for 10 hr, alternating with 23° for 14 hr, was markedly increased by seed treatment with 0.5 mM fusicoccin (FC). Neither gibberellic acid (GA) nor kinetin (K) were effective in improving emergence when used alone. The combination of FC with GA or K appeared to give a synergistic enhancement of emergence rate. The radicle elongation of seedlings was reduced by seed treatment with FC, K, or combinations of FC, GA, and K in tests at 20°. The greatest reductions were caused by combinations that included FC. The inhibiting effect of FC on radicle growth was reduced by using a concentration of 0.05 mm. Treatment with 0.05 mm FC resulted in slower emergence but gave the same total emergence as 0.5 mm FC at high temperature. Both FC and GA stimulated hypocotyl elongation.

Open Access

Abstract

Carbohydrate content varied among cultivars of bermudagrass (Cynodon dactylon L.) at 3 sampling dates during dormancy and greenup. Sucrose and starch decreased in rhizomes between March and May while reducing sugars remained constant. Concentration of stored carbohydrate was correlated positively with the number of rhizomes near the soil surface during winter and early spring. Spring deadspot injury ranged from 60% of the plot area for ‘KSU, (Kansas State University) T-5, to zero for ‘Royal Cape’, ‘Mich. C-53’, ‘Midway’ and ‘KSU D-17.’ Earliest to greenup in spring was ‘KSU T-3’ while ‘KSU T-5’, ‘F-4’, ‘Md. 23’, ‘24’ and ‘U-3’ were only 13-33% green on the same date. Injury was less severe where cultivars utilized carbohydrate and greened early in the spring. Early greenup was associated with thinner layers of thatch. There was no association between thickness or number of rhizomes and spring deadspot.

Open Access

Abstract

Mechanical pollination trials using air blasts and vibration to distribute pollen were conducted on the highbush blueberry, Vaccinium corymbosum cvs. ‘Jersey’ and ‘Rubel’. Neither treatment nor a simultaneous combination of the two gave commercial fruit set for either cultivar. Mechanical trials on the ‘Rubel’ cultivar indicated almost total failure to effect pollination. Production from ‘Jersey’ cultivar mechanical pollination trials was more promising. However, low seed numbers indicated that the increased production of this cultivar might be due to its tendency to set fruit parthenocarpically.

Open Access

Abstract

In the paper “Effect of Plant Population and Planting Date on Root and Starch Production of Buffalo Gourd Grown as an Annual” by J.M. Nelson, J.C. Scheerens, J.W. Berry, and W.P. Bemis [J. Amer. Soc. Hort. Sci 108(2): 198–201, 1983), 2 incorrect quadratic equations are given. In Fig. 3 and on page 199, column 2, line 11, the equation Y = 676 + 0.8X - 0.000072X2 should be Y = 6.8 x 103 + (8.0 x 10-2)X - (7.2 x 10-8)X2. In Fig. 4, the equation Y = 462 + 1.27X - 0.000145X2 should be Y - 4.6 x 102 + (1.3 x 10-2)X - (1.5 x 10-8)X2.

Open Access

Abstract

The buffalo gourd (Cucurbita foetidissima HBK) produced root yields as high as 34,550 kg/ha with a root starch content of 63.5% on a dry weight basis at a 920-m elevation site. A quadratic relation between root yield and plant population showed maximum yield at 550,000 plants/ha. No clear relation was observed between root starch content and plant population. An April planting resulted in higher root and starch yields than a July planting, at a 370-m elevation site. Vine growth appeared to be restricted when maximum air temperatures were above 40°C.

Open Access

Abstract

Ammonia volatilization from urea-N applied to Kentucky bluegrass ( Poa pratensis L. ‘Bensun’) was investigated using a chamber trapping procedure. Urea was spray-applied in a 0.2 cm depth at N of 5 g·m−2 with and without additional irrigation of 0.5, 1, 2, or 4 cm. Losses up to 36% of the applied N occurred when urea was applied without irrigation. Supplemental irrigation of as little as 1.0 cm reduced the loss to 3-8%, while a 4.0-cm irrigation further reduced losses to about 1%. Of the ammonia volatilized, most was lost in the first 24 hr. Maximum N loss was associated with the thatch layer, a zone having high urease activity.

Open Access

Symptoms of chlorotic leaf distortion (CLD) develop on vigorously growing sweetpotato (Ipomoea batatas) plants during sunny weather. They include chlorosis and twisting of young, expanding leaves and the appearance of white material on the adaxial leaf surfaces. The white material consisted of extramatrical fungal mycelia and Fusarium macroconidia. Fusarium lateritium Nees was isolated from surface-sterilized vine segments, leaf primordia, apical meristems, flower parts and true seeds of plants with CLD. Meristem-tip-culture-derived plants (mericlones) did not develop symptoms when grown for extended periods under disease-conducive conditions in the greenhouse. The fungus was not isolated from mericlones or other plants which had remained symptomless in the greenhouse but was isolated from lower nodes of symptomless plants from growers' fields. Symptoms developed on 84% of 185 mericlones of nine sweetpotato genotypes inoculated with F. lateritium isolated from CLD-affected plants. The pathogen was reisolated only from inoculated mericlones.

Free access

Boron deficiency in fresh-market tomatoes (Lycopersicon esculentum Mill.) is a widespread problem that reduces yield and fruit quality but is often not recognized by growers. Tomatoes were grown in field and hydroponic culture to compare the effects of foliar and soil applied B on plant growth, fruit yield, fruit quality, and tissue nutrient levels. Regardless of application method, B was associated with increased tomato growth and the concentration of K, Ca, and B in plant tissue. Boron application was associated with increased N uptake by tomato in field culture, but not under hydroponic culture. In field culture, foliar and/or soil applied B similarly increased fresh-market tomato plant and root dry weight, uptake, and tissue concentrations of N, Ca, K, and B, and improved fruit set, total yields, marketable yields, fruit shelf life, and fruit firmness. The similar growth and yield responses of tomato to foliar and root B application suggests that B is translocated in the phloem in tomatoes. Fruit from plants receiving foliar or root applied B contained more B, and K than fruit from plants not receiving B, indicating that B was translocated from leaves to fruit and is an important factor in the management of K nutrition in tomato.

Free access